Automatic wind and rewind system for strip materials



Dec. 1, 1953 GREENE 2,661,163

AUTOMATIC WIND AND REIWIND SYSTEM FOR STRIP MATERIALS Filed Aug. 25, 1948 3 Sheets-Sheet 1 Q 1 K3 1 Q R O c K? F'] 3 \l 1 l g WA 2 INVENTOR. P560) 5 kEi/VE ATTOE/VEKS' P. E. GREENE Dec. 1, 1953 AUTOMATIC WIND AND REWIND SYSTEM FOR STRIP MATERIALS 3 Sheets-Sheet 2 Filed Aug. 25, 1948 IINVENTOR. Faecy 5 G'kffA/E A TTOE/VEVS P. E. GREENE Dec. 1, 1953 AUTOMATIC WIND AND REWIND SYSTEM FOR STRIP MATERIALS 3 Sheets-Sheet 3 Filed Aug. 25, 1948 INVENTOR. Paecy f 6956/VE [@myon 1 Patented cc. l, 1953 AUTOMATIC WIND AND REWIND SYSTEM FOR STRIP MATERIALS Percy E. Greene, Denville, N. J assignor to Leventhal Patents, Inc., New York, N. Y., a corporation of Delaware Application August 25, 1948, Serial N 0. 45,997

10 Claims. (01. 242-55) This invention comprises essentially a new and improved mechanism for winding back-and-forth from one drum to another an elongated strip of material such as a motion picture film. It has for its general object the provision of such a mechanism improved by the incorporation therein of one or more of the following features: (0.) Improved means for automatically reversing the direction of winding when all the useful portion of the film has been wound through the machine in one direction; (b) improved means for insuring that the unwinding from one drum will automatically cease before a predetermined length of a leader or trailer strip binding the fihn to the wheel is also unwound from the drum; and particularly (0) means insuring that the wind and rewind mechanisms will automatically adjust themselves to operate in the foregoing manner for any size of film roll, i. e., for any of a number of film rolls of dififerent diameters-the latter means functioning without the necessity of any effort on the part of the operator additional to that normally required for the inser tion of the film roll into the mechanism.

While the invention finds application in any sort of a system for winding strip-like material from one end to the other and back again, it in parties.-. advantageous application in co cion with the inding and unwinding of photographic film for motion picture projection or even for the processing thereof. Rewinding is of course always necessary in the projection of motion picture film; cyclic back-and-forth winding is however especially desirable in what are known as automatically repeating projectors 1 the ii after projection, is automatind is either projected again imin condition operator film ord, arily va y in outer diameter from roll nd ached to their opposite ends or trai er strips which serve to attach the c the ejected portion to the drums upon which it is wound. With automatic repetition action, it is usually desirable that these tder or trail strips remain attached to the at all t .es and therefore that they not be wound o" the drums during the automatic bacloand forth winding of the film.

Among e erata of systems of the foregoing character are the following: The mechanism should be so arranged that power will be transferred smoothl and in proper time backan iorth between the supply drum from which the film is normally unwound during actual projection and the take-up drum onto which it is collected. The timing of power transfor should be such that it will occur immediately at the moment when all of the projeotable portions of the film have been unwound or rewound and before either the leader or trailer strips can leave, either in unwinding or rewinding, their associated drums completely (preferably no more than necessary to permit the projectable portion highly desirable that a drum carrying any normal amount of film may be introduced into the system without the necessity of the operator making adjustments for the length, this being accomplished automatically so that the system will accommodate rolls of film of varying length, that is, varying diameters.

The features believed to constitute the invention in its broadest scope are pointed out in the appended claims. It is believed, however, that the invention itself will best be understood by those skilled in the art by reference to the following specification and the accompanying drawings which illustrate one preferred embodiment thereof. In the drawings: The Fig. 1 represents schematically the wind-andrewind system of a motion picture projecting machine omitting for the sake of clarity elements not constituting parts of the invention such as the projection lenses, shutter mechanisms etc. Figs. 2 and 3 are cross sections along dotted line II--II of Fig. 1 in a plane normal to the drawing and constitute detail illustrations of a linkage interlocking arrangement of Fig. 1 shown respectively in its unlocked and locked position; Figs. 4 and 5 are views similar to Fig. 1 showing the system in its extreme opposite positions, Fig. 4 showing the film in its position ready for the commencement of projection; and Fig. 5 showing it in its position ready for the commencement of rewinding; while Fig. 6 represents an alernative embodiment employing mechanical power transfer means in the place of the electrical means of the preceding figures.

Broadly speaking, the heart of the invention resides in the provision of means equivalent to the mechanical interlinkage system between the film supply reel or drum I and the film-collecting or take-up reel or drum 2 between which the film 3 is wound back-and-forth. The interlink age system is so arranged that it will deenergize the motor 4 driving the drum 2 at precisely the time when all of the projectable picture portion of the film has passed through the machine and before the trailer strip 9 (the relatively short length of blank tape securing the trailing end of the film to the drum I as best indicated in Fig. 5) has been wound oif the drum I. At that time movable contacts I and 8 of the limit switch arrangement comprising contacts I, 8 and 9 (stationary) associated with the mechanical interlinkage system are brought together (as in Fig. 5) by upward motion of contact 8 and operate to deenergize the motor 4 of drum 2 and energize the driving motor 5 for the drum I so that film automatically begins to rewind. Again the linkage system is so arranged that the rewinding will cease at precisely the time when all of the picture portion of the film has been rewound but before the leader strip I0 (another short length of blank tape best indicated in Fig. 4 as securing the leading film end to the drum 2) has been wound ofi. At this time, the contacts 8 and 9 are brought together (as in Fig. 4) and operate to deenergize motor 5 and energize motor 4 so that projection automatically recommences. This cycle of winding and rewinding may be continued automatically unless stopped by the intervention of the operator or otherwise. For example, it may be stopped manually or automatically after the completion of the re- :7.

winding in order that the machine may be left in condition ready for reprojection at the will of an operator. The specific mechanism to accomplish the foregoing mode of operation is as follows:

The roller II is adapted to engage the outermost layer of the film on the drum I. As will be explained in greater detail hereinafter, the roller II is locked approximately at a position (radially from the axis of drum I) corresponding to the maximum extent of the film roll (less leader strip) on the drum I, thus completely separating it from the emulsion bearing surfaces of all but the very outward film layers. The

roller I I controls the up-and-down movement of a hollow tube I2 in accordance with the maximum amount of film on the drum I and, in that respect, the roller may be considered as constituting with the tube I2 a follower system which automatically measures the amount of film introduced. Tube I2 has a longitudinal slot 52A for purposes to be described. The action between the tube l2 and the roller II is effected through the medium of the lever system I3 and M which is pivoted at a suitable fixed pivot point I5. A similar roller I6 guided by lever I'I pivoted at I8 is arranged to ride on the film on the drum 2 and in this case the roller is permitted to ride directly on the entire lateral dimension of the film inasmuch as the emulsion is now on the underside by virtue of the fact that the film surfaces have been reversed on the drum 2. The roller I6 has attached thereto a rod I9 which extends into the hollow tube I2 and may be considered as constituting with the roller IS a follower system following the instantaneous position of the last layer of film on the drum 2. In this respect the action of the roller It differs from that of the roller I I in that it continuously follows the diameter of the roll whereas the on the drum I.

roller II is locked in a position corresponding approximately to the maximum outer extent of the roll.

In order to guide tube I2 and also to permit a certain amount of lateral movement thereof as necessitated by the rotation of the lever systems (I3, I4 and I1), any suitable means such as the block 20 may be provided and afiixed to a base 2| which constitutes a support for the entire mechanism. Tube I2 may extend through any suitable laterally extending slot in block 29 which slot will have sufficient extent to accommodate any necessary lateral movement of tube I 2.

Contacts I and 8 are afi'ixed to tube I2 and rod I9 respectively, while contact 9 is affixed to base 2| except to the extent that it is preferably mounted on a spring upwardly biased plunger 9A which permits contact 9 to move slightly downwardly to permit roller It to drop all the way to the reel 2 when no leader strip I9 is on it. The extent of movement of plunger 9A may be visualized by comparing Figs. 1 and i.

As to the functioning of the mechanisms thus far described, it will be apparent that the rod I9 will move up-and-down within tube I2 in accordance with the winding and unwinding of the film on the drum 2. This up-and-down motion of the rod I9 is caused to control the selective energization of the motors i and 5, which alternately drive the drums I and 2, through the medium of the limit switch arrangement in the following manner: When, during automatic back-and-forth winding, rod I9 reaches its lowermost point of excursion (corresponding as in Fig. 4. to the condition in which drum 2 has only the leader ID on it), the contact between contacts 8 and 9 which then begins will cause a deenergization of the motor 5 driving the drum I and an energization of the motor 3 driving the drum 2. Thereby any rewinding of the film from the drum 2 onto the drum I is stopped and the motion reversed to resume projection. Conversely, when the rod I9 together with the contact 8 reaches the uppermost point of its excursion (corresponding to the condition in which drum I has only trailer 6 on it, as in Fig. 5) the contact between contacts I and 9 will cause deenergization of motor 4 and energization of motor 5 whereby the rewinding process is initiated.

It is particularly to be noted that the fact that the contact I moves with the tube I2 causes it to be automatically positioned to accommodate the entire action to different amounts of film Thus, by virtue of the fact that a larger winding on the drum I will raise and lock contact I at a higher position, the motor 5 will not be deenergized during the rewinding process until a later time at which the entire amount of the film has been rewound. The converse action with respect to the contact 9 is unnecessary for which reason it is fixed in position except to the extent already indicated.

The action of the automatic accommodation to film roll size of the follower system constituting the roller II and the tube I2 includes the locking action of the inter-coupling system between the rod I9 and the hollow tube I2. This is best illustrated by the Figures 2 and 3. It will be seen there that the fixed block 20 has mounted thereon a rotatable dog 2IA which is pivoted at 22 and biased counterclockwise by the spring 23 to such a position that it will lock by means of dog arm 25 the tube I2 against vertical movement, as indicated by the Figure 3. Attached to the rod I9 is a pin 26 which slides in a suitable longitudinal slot IZA in the tube I2. When the rod i9 together with the pin 2t is in its lowermost position as indicated by the Figures 1 and 2, the pin will engage the surface 21 of the dog 2 IA and thereby rotate it clockwise in order to release the dog arm 25 from engagement with the tube i2. Obviously therefore, the tube I2 will be free to move up-and-down in the vertical direction when thus unlocked.

The function of this locking arrangement is as follows. When the operator places a given amount of film on the drum I, the roller I I and, thus, tube I2 will drop to a position corresponding to the maximum radial extent of the film winding,

that is, the follower system will accommodate itself to the outermost layer or" a newly added roll of film on the reel i. This, as already explained, is by virtue of the lever system the arms i3 and it of which are afiixed to each other. (Contact 8 will already have engaged contact 9 and depressed plunger 9A.) The pin 26 is so positioned that when the roller i6 is resting on the outermost layer of a predetermined amount of leader strip on drum 2 (or is at any lower position such as when drum 2 is empty) the rod 39 and the pin 26 will hold the locking dog 21A, or rather its arm 25, out of contact with the tube i2; however, as soon as a picture portion begins to pass through the projector, the rod I9 begins to rise with the collection of an additional small amount of leader on the reel 2 over and above the predetermined amount, and the pin 26 will rise correspondingly and release the dog arm 25 which thereupon locks the tube I2 in a fixed position at precisely the time when a predetermined amount of leader II] has collected on drum 2, or at precisely the time when picture portions start through the projector. The tube i2 will remain thus locked throughout all subsequent wind and rewind cycles and the system will then wind and rewind continuously and yet stop rewinding and reverse at exactly the right moment when all of the picture portion of the film has been rewound but before the leader strip it has been wound of! drum 2 to more than a predetermined extent determined by the setting of pin 25.

It will be apparent therefore that the interlinkage system automatically adjusts itself to film rolls of diiierent diameters. The action of the pin 26 in releasing the dog 2| just shortly after a predetermined small amount of film or leader has been wound on the drum 2 has the further advantage that it insures that the trailer strip 5 will not run off the reel I at the end of the feed cycle because the locking action sets the contact 7 closer to contact 3 by an amount which results in a predetermined number of leader layers on drum 2. It follows that contact 1 will be contacted when an equal number of layers of trailer remain on drum I. The mechanism will thus adjust itself to allow several wraps of the trailer or the leader to remain on the respective drums on both ends of the films excursion.

As a conveni nt way of conforming the action of the follower system associated with the reels I to obtain the foregoing results, I have used drums having hubs of identical dimensions and I have chosen to make the levers I3, is and I? of the same lengths and to place the pivot point in the same relative position with respect to the center of the drum l as pivot point 58 is with respect to the center of drum 2. Because of this i the solenoids 33 and 3d.

6 I it will be apparent that in one projection run the roller I6 will climb the same distance away from the hub surface of the drum 2 as the roller I I was initially set away from the hub surface of drum I. Therefore, if the initial locked setting of contact 7 be such that it is then separated from contact 8 by a distance just equal to the radial thickness of the film picture portion, the reversals will occur at precisely the ends of the picture portion. It will be understood, of course, that other i geometrical arrangements including diirerent dimensions for the respective elements may be devised with the same results. For example, it may be necessary to make allowance for different size drums I in practice. of drum 2 might be equal to the diameter of the largest standard reel drums I and the operator might use different methods of overcoming diameter inequalities. He could, in the case of drums I having smaller hub diameters, make up the difference in diameters by adding an appropriate amount of blank trailer to build up the required diameter. Alternatively, he might use a fixed diameter for all drums I and adjust the interlinkage system accordingly.

It will be understood also that numerous suit able circuit arrangements may be employed for the reversal for the motors i and 55 upon operation of the limit switch arrangement. Therefore I have shown one such circuit which is illustrative only in a general way. This may com-1 prise, for example, a relay 28 so arranged that it will transfer the power from a conventional power line 29 from one motor to the other in accordance with the aforedescribed behavior of the limit switches. Relay 2% is shown as having a contact-armature 3% adapted to be switched either to the right or to the left to make contact with the contact 3| or the contact 32 by means of As indicated, the solenoid 33 will be energized by means of a battery 35 upon contact between the contacts I and 8; while the solenoid 34 will be similarly energized by the bringing together of the contacts 8 and Snap action for the armature 30 may be provided by means of an ofi-center spring 35 in a well known manner. It will be readily apparent from the circuit that the energization of the solenoid 33 will attract the armature 38 in such manner as to open the circuit of motor 3 and close the circuit line when it is desired to shut down the operation of the entire mechanism. It will be understood, of course, that suitable means may be devised to provide for automatic opening of switch 31 at the end of the rewind if such result be desired. For purposes of simplification such means ing the film to take up slack.

In the Figure 6 there is shown an alternative mechanical arrangement for transferring power between drums. For the purposes of clarity of illustration the detailed arrangements of the {motor and the driving systems are omitted and ".the place of the contacts 1, 8 and 2 there are' In practice, the diameter 7, substituted plungers 4i and 42 and actuator 43; The actuator 43 corresponding to the contact 8 is affixed to the red I 9 and adapted so that when it reaches the extreme positions of its excursion it will press upon the plungers M and 62 to oper-. ate the clutch transfer system 44. When the actuator 43 is at the lowermost position of its eX-. cursion it will press upon the plunger 42 which thereupon pushes a flexible wire 45 through the hollow core of the tube 46. To the opposite end of the wire 45 is afiixed a lever 41 pivoted at 48 and provided with an off-center biasing spring as. The actuation of this lever by the wire will cause motion of the clutch member 59 to the left to permit the same to engage the driving gear The converse action takes place when the actuator 43 presses upon the plunger 41 which thereby actuates a similar flexible wire member 52 within the tube 53. This thereupon acts to move the clutch member 5%! to the right whereupon it engages the gear 54. It will be understood that numerous mechanical arrangements will occur to those skilled in the art which will utilize this action for the transfer of power from one motor to the other.

While I have shown and described a particular embodiment of the invention, it will be understood that numerous modifications therecf will occur to those skilled in the art. All such as fall within the true spirit and scope of my invention, I aim to cover by the appended claims.

I claim:

1. In combination in a machine for winding variable length elongated strips back-and-forth from one roll to another, a first drum and driving means for driving the same to wind a strip thereon, a second drum and driving means for driving the same to wind said strip thereon, a follower system adapted to follow accumulations of said strip on said first drum and to be fixed at a posi\- tion corresponding to a predetermined approximately maximum extent of said strip thereon and including a first member movable through positions corresponding to the instantaneous amounts of said strip on said first drum, a follower system adapted to follow accumulations of said strip on said second drum for following the instantaneous amounts of said strip thereon and including a second member movable through positions corresponding to the instantaneous amounts of said strip on said second drum, said movable members being movable with respect to each other, a system interconnecting said movable members including means actuated by the motion of said second member to a position colresponding to the accumulation of a predetermined small extent of said strip on said second drum for preventing further motion of said first member, and means on said movable members responsive to further movement of said second member to a position corresponding to the accumulation of a predetermined approximately maximum extent of said strip on said second drum for deenergizing said second driving means and energizing said first driving means, andrasponsive to movement of said second member to a position corresponding to said predetermined small extent of said strip on said second drum 7 for deenergizing said first and energizing said second driving means.

2. A combination as in claim 1 in which said strips include leader and trailer portions on op,- posite ends thereof, said means in said interconnecting system being constructed and arranged to fix said first member upon accumula- 8.. tion of a predetermined amount of leader portion on said second drum.

3. A combination as in claim 2 in which said means on said movable members are so positioned as to energize and deenergize said driving means at moments when predetermined lengths of said leader and trailer portions remain on said drums.

4. A combination as in claim 2 in which said means on said movable members are so positioned as to reverse the direction of driving of said drums at moments when predetermined lengths of said leader and trailer portions remain on said drums.

5. A combination as in claim 1 in which said members have associated therewith rollers adapted to ride on the periphery of said rolls, saie first member comprises a hollow tube, said second member comprises a rod movable within said tube, and said locking means comprises a dog mechanism biased to engage and lock said tube and adapted to be released from looking engagement by motion of said second member,

6. A combination as in claim 5 in which said deenergizing and energizing means on said movable means comprises mutually contactable members one on each of said members and in contact when said second member is in its posi tion corresponding to the accumulation in said second roll of approximately said predetermined radial accumulation of said strip in said first roll, and mutually contactable members one on said second movable member and one fixed relative thereto and in contact when said second member is in its position corresponding to said. predetermined radial accumulation of said. strip in said second roll.

7. In combination in a machine for winding radially accumulating rolls of variable length motion picture film strips baclz-and-forth from one roll to another, a first drum and driving means for driving the same to wind a strip thereon, a second drum and driving means for driving the same to wind said strip thereon, a first roller adapted to follow accumulations of said strip on said first drum and to be locked at a position corresponding to a predetermined approximately maximum radial extcnt of said strip thereon, a first member connected to said first roller and movable therewith through positions corresponding to the instantaneous radial crtents of said strip on said fi st drum until looked as hereinafter indicated, a second roller adapted to follow accumulations of strip on said second drum for following the instantaneous radial extent of said strip thereon, a second member connected to said second roller and movable therewith through positions corresponding to the instantaneous radial extents of said strip on said second drum, said movable members being movable with respcct to each other, a system interconnecting said movable membcrs including locking means actuatable by said second member upon motion of said second roller a predetermined small radial distance away from said second drum for locking said first roller and first member at a position corresponding to said predetermined maximum radial extent of said strip on said first drum, and means on said movable members responsive to movement of said second member to a position corresponding to the accumulation of a predetermined approximately maximum radial extent of said strip on said second drum for deenergizing said second driving means and energizing said first driving means, and responsive to movement of said second member to a position corresponding to said predetermined small radial extent of said strip on said second drum for deenergizing said first and energizing said second driving means.

8. A combination as in claim 7 in which said strips include leader and trailer portions on opposite ends thereof, said means in said interconnecting system being constructed and arranged to lock said first roller and first member upon accumulation of a predetermined radial extent of leader portion on said second drum.

9. A combination as in claim 8, in which said means on said movable members are so positioned as to energize and deenergize said driving means at moments when predetermined lengths of said leader and trailer portions remain on said drums.

10. A combination as in claim '7 in which said first member comprises a hollow tube and said second member is a rod movable within said first member, and said locking means comprises a dog mechanism biased to engage and lock said tube and adapted to be released from locking engagement by motion of said second member.

PERCY E. GREENE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,695,857 Proctor Dec. 18, 1928 FOREIGN PATENTS Number Country Date 464,943 Great Britain Apr. 28, 1937 

